Cumulative trauma disorders have emerged as a significant occupational health problem. In recent testimony before the House Government Operations Subcommittee in employment and housing, cumulative trauma disorders were labeled "the number one occupational hazard of the 1990's". Numerous case reports and newspaper articles have highlighted this health concern, but needed epidemiologic data are sparse. Carpal tunnel syndrome (CTS) is one of the most commonly reported and widespread of the cumulative trauma disorders. This study will examine the magnitude of carpal tunnel syndrome and also study work related risk factors for these cumulative injuries. The clerical and trade occupations of data entry operators, court clerks, carpenters, pipe fitters are selected based, on ergonomic considerations, and elementary school teachers are selected as a reference group. The research design includes a job/task exposure matrix integrated with the epidemiologic methods, and a two-stage design incorporating a cross-sectional survey and a nested case-control study of 100 CTS cases and 100 controls. The larger sample size obtainable in the cross-sectional survey will provide better estimates of CTS prevalence among the selected occupational groups, and the case-control phase is designed to better address specific occupational risk factors for CTS. Abbreviated electrodiagnostic testing will be used to examine clinical and diagnostic issues of CTS through comparisons of results derived from self-reporting of symptoms, clinical tests and the median nerve sensory and motor nerve conduction tests. This epidemiologic information will help to establish future intervention and prevention programs and to identify future research needs.